Densely Connected Network with Time-frequency Dilated Convolution for Speech Enhancement

The data driven speech enhancement approaches using regression-based deep neural network usually result in enormous number of model parameters, which increase the computational load and the difficulty of model training. In order to improve the model efficiency, we propose a densely connected network with time-frequency (T-F) dilated convolution for speech enhancement. The T-F dilated convolution block is designed to enlarge the receptive field and capture the contextual information in both temporal and frequency domains. Considering the computational efficiency, the 1-D convolution with the bottleneck structure is exploited in the T-F convolution block. Each T-F convolution block is then densely connected to ensure maximum information flow between layers and alleviate the vanishing gradient problem of the network. The experimental results reveal that the proposed scheme not only improves the computational efficiency significantly but also produces satisfactory enhancement performance comparing the competing methods.